Removal and mineralization of prednisolone from water by using homogeneous and heterogeneous electro-Fenton processes

Abstract

Prednisolone (PRD) is a popular synthetic corticosteroid medication that discharging it into wastewater raises potential environmental issues. In terms of treatment methods, advanced oxidation processes (AOPs), such as the electro-Fenton (EF) process, have been proposed as a potential option. This study investigates the removal of PRD from aqueous media using both homogeneous and heterogeneous EF processes. A reduced graphene oxide/Tin (IV) oxide/stainless steel mesh (rGO/SnO2/SSm) composite system was prepared as the cathode electrode, and a reduced graphene oxide/magnetite/cotton fabric (rGO/Fe3O4/CF) composite system was prepared as the heterogeneous catalyst. The optimization of process parameters for each system was carried out using response surface methodology (RSM). The removal efficiencies of PRD were determined under optimal conditions. The homogeneous EF process achieved an 83.79% removal efficiency, while the heterogeneous EF process achieved a 74.62% removal efficiency. The properties of the heterogeneous catalyst and the cathode electrode were investigated using SEM, XRD, FT-IR, CV and EDX analyses. GC-MS and TOC analyses were performed to evaluate degradation intermediates and mineralization efficiency. The stability and reusability of the heterogeneous catalyst and the synthesized cathode electrode were evaluated. These findings offer insightful information about the use of EF methods for PRD removal.